Magnetic Fields toward Ophiuchus-B Derived from SCUBA-2 Polarization Measurements

We present the results of dust emission polarization measurements of Ophiuchus-B (Oph-B) carried out using the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) camera with its associated polarimeter (POL-2) on the James Clerk Maxwell Telescope in Hawaii. This work is part of the B-fields in Star-forming Region Observations survey initiated to understand the role of magnetic fields in star formation for nearby star-forming molecular clouds. We present a first look at the geometry and strength of magnetic fields in Oph-B. The field geometry is traced over ~0.2 pc, with clear detection of both of the sub-clumps of Oph-B. The field pattern appears significantly disordered in sub-clump Oph-B1. The field geometry in Oph-B2 is more ordered, with a tendency to be along the major axis of the clump, parallel to the filamentary structure within which it lies. The degree of polarization decreases systematically toward the dense core material in the two sub-clumps. The field lines in the lower density material along the periphery are smoothly joined to the large-scale magnetic fields probed by NIR polarization observations. We estimated a magnetic field strength of 630 ± 410 μG in the Oph-B2 sub-clump using a Davis–Chandrasekhar–Fermi analysis. With this magnetic field strength, we find a mass-to-flux ratio λ = 1.6 ± 1.1, which suggests that the Oph-B2 clump is slightly magnetically supercritical

Contribution and functional connectivity between cerebrum and cerebellum on sub-lexical and lexical-semantic processing of verbs.

Language comprehension involves both sub-lexical (e.g., phonological) and lexical-semantic processing. We conducted a task using functional magnetic resonance imaging (fMRI) to compare the processing of verbs in these two domains. Additionally, we examined the representation of concrete-motor and abstract-non-motor concepts by including two semantic categories of verbs: motor and mental. The findings indicate that sub-lexical processing during the reading of pseudo-verbs primarily involves the left dorsal stream of the perisylvian network, while lexical-semantic representation during the reading of verbs predominantly engages the ventral stream. According to the embodied or grounded cognition approach, modality-specific mechanisms (such as sensory-motor systems) and the well-established multimodal left perisylvian network contribute to the semantic representation of both concrete and abstract verbs. Our study identified the visual system as a preferential modality-specific system for abstract-mental verbs, which exhibited functional connectivity with the right crus I/lobule VI of the cerebellum. Taken together, these results confirm the dissociation between sub-lexical and lexical-semantic processing and provide neurobiological evidence of functional coupling between specific visual modality regions and the right cerebellum, forming a network that supports the semantic representation of abstract concepts. Further, the results shed light on the underlying mechanisms of semantic processing and contribute to our understanding of how the brain processes abstract concepts

Activation maps for the comparison between mental and motor verbs.

Graphical representation of GLM’s results, brain regions activated in the contrast mental > motor verbs in red, same contrast when the effect of visual processing (i.e., symbols) is removed, in green, and when the effect of phonological processing (i.e., pseudo-verbs) is removed, in blue. Coordinate z of multislices in cerebellum: a = : a = -24, b = -29, c = -34, and d = -39. Color bars show z scores. LH: left hemisphere; RH: right hemisphere.</p

PPI results for the comparison between mental and motor verbs.

Graphical representation of PPI results with the R-cerebellum seed, brain regions functionally connected in the contrast mental > motor green. Color bar shows z scores. Coordinate z slice in cerebellum = -29. LH: left hemisphere; RH: right hemisphere.</p

Activation maps for verbs and pseudo-verbs with respect to symbols.

Graphical representation of GLM’s results, brain regions activated in the contrast verbs > symbols in red, and pseudo-verbs > symbols in aqua. Coordinate z of multislices in cerebellum: a = -24, b = -29, c = -34, and d = -39. Color bars show z scores. LH: left hemisphere; RH: right hemisphere.</p

Correlations among scores on behavioral tasks.

Vocabulary task of WAIS-IV, verb, semantic, and phonological fluency (f).</p

Brain areas exhibiting significant connectivity during motor > pseudo verbs and mental > pseudo verbs, according to PPI analysis with seeds in L-LOC, L-SMA and R cerebellum.

The x, y, and z coordinates are in MNI space, regions were labelled according to Harvard-Oxford Cortical and Subcortical Atlases in FSLVIEW. L = Left region or hemisphere. R = Right region or hemisphere. (PDF)</p

PPI results for motor, mental and pseudo verbs with respect to symbols.

Graphical representation of PPI results with seeds in L-LOC, L-MTG, L-SMA, and R-cerebellum, brain regions functionally connected in the contrast motor > symbols in red, mental > symbols in green, and pseudo-verbs > symbols in blue. Color bars show z scores. LH: left hemisphere; RH: right hemisphere.</p

Activation maps for the comparison between verbs and pseudo-verbs.

Graphical representation of GLM’s results, brain regions activated in the contrast verbs > pseudo-verbs in red, and pseudo-verbs > verbs in aqua. Coordinate z of multislices in cerebellum:: a = -24, b = -29, c = -34, and d = -39. Color bars show z scores. LH: left hemisphere; RH: right hemisphere.</p